Expert: James Gort - 9/20/2011

Question
Hello, My name is Matt. I'm in the 8th grade and I'm working on a science fair project this year that involves trying to prove the Yarkovsky Effect. I'm prepared to build out of plexiglass, a type of vacuum chamber that would show that by painting an asteroid(sytrofoam)white and one black, that the asteroid can be propelled.
I'm looking for advice on making my experiment more effective. Some of my concerns are whether I might see a result, even if very slight. Also, after making the vacuum environment, how might gravity affect the results? I've found very little information regarding this idea through my research, other than scientists are doing experiments with software. I'd really like to do a hands-on project.
My hypothesis is basically that, by adding a reflective surface to the asteroid that propulsion will be created, therby altering its orbit.
I sincerely appreciate any help or advice you can provide me.
Thank you in advance,
Matt

Answer
Hi Matt,

Just a suggestion. I think this is still a good idea, but keep in mind that results will be difficult to obtain. Nevertheless, a "null" result is still a result, and can give an upper limit to the phenomena you're trying to measure. So you could try constructing a Nichols radiometer (http://en.wikipedia.org/wiki/Nichols_radiometer), and show how this demonstrates the Yarkovsky effect. Your posters should illustrate the Yarkovsky effect, and its potential effect on asteroids' orbits - even the possibility that the effect could result in earth colliding with an asteroid, and strategies (using the Yarkovsky effect) for deflecting near-earth objects.

If the Nichols radiometer you construct doesn't work (i.e., there's no deflection), this will just demonstrate how small an effect it is! You can even compare it the the "gravitational effect" - that's pretty small, too - but it still keeps the earth (and asteroids) in orbit. If you're up to building another device, try the Cavendish experiment (http://en.wikipedia.org/wiki/Cavendish_experiment) to show how very small the gravitational force actually is (to compare it to the Yarkovsky effect).

But I warn you - neither experiment may actually work, but (in my humble opinion), that's still a valid result.

Good luck.

Cheers,

Prof. James Gort